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arXiv · hep-ph/0606254

The Two-loop Anomalous Dimension Matrix for Soft Gluon Exchange

S. Mert Aybat·Lance J. Dixon·George Sterman
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Abstract

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions. We compute this matrix directly for arbitrary 2 to n massless processes for the first time at two loops. Using color generator notation, we show that it is proportional to the one-loop matrix. This result reproduces all pole terms in dimensional regularization of the explicit calculations of massless 2 to 2 amplitudes in the literature, and it predicts all poles at next-to-next-to-leading order in any 2 to n process that has been computed at next-to-leading order. The proportionality of the one- and two-loop matrices makes possible the resummation in closed form of the next-to-next-to-leading logarithms and poles in dimensional regularization for the 2 to n processes.

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S. Mert Aybat, Lance J. Dixon, George Sterman. 2006-06-23. The Two-loop Anomalous Dimension Matrix for Soft Gluon Exchange. https://doi.org/10.1103/physrevlett.97.072001

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